Abstract

Sixty premenopausal women (age 25-50) finished a 16 week randomized controlled trial looking at the effects of different jump programs on hip and spine bone mineral density (BMD). Subjects were randomly assigned to a control group or one of two jumping groups. The Jump 10 group performed 10 jumps with 30 seconds of rest between jumps, twice daily, while the Jump 20 group performed the same protocol but with 20 jumps. At 8 weeks, BMD percent change (%Δ) at the hip was significantly different among groups when age, weight change, and subject compliance were simultaneously adjusted. In particular, the Jump 20 group had a greater %Δ in hip BMD compared to controls. However, %Δ in BMD for the neck of the hip (NOH), trochanter, or spine was not different among groups at 8 weeks. Following 16 weeks of jumping, BMD %Δ at the total hip and trochanter were significantly different among groups after adjusting for all covariates. Specifically, at the hip and trochanter, the Jump 10 and Jump 20 groups showed significantly greater %Δ in BMD compared to controls. There were no significant differences among groups for the BMD %Δ at NOH or spine at 16 weeks. Within-group analyses revealed no significant changes from baseline to 16 weeks for the jumping groups, but controls lost significant BMD. In conclusion, after 16 weeks of high-impact jump training, BMD at the hip and trochanter can be improved by jumping 10 or 20 times, twice daily, with 30 seconds of rest between each jump, compared to controls.

Degree

PhD

College and Department

Life Sciences; Exercise Sciences

Rights

http://lib.byu.edu/about/copyright/